C++ LogReader::startListener方法代码示例

// Foreground waits for exit of the main persistent threads
// that are started here. The threads are created to manage
// UNIX domain client sockets for writing, reading and
// controlling the user space logger, and for any additional
// logging plugins like auditd and restart control. Additional
// transitory per-client threads are created for each reader.
int main(int argc, char* argv[]) {
    // logd is written under the assumption that the timezone is UTC.
    // If TZ is not set, persist.sys.timezone is looked up in some time utility
    // libc functions, including mktime. It confuses the logd time handling,
    // so here explicitly set TZ to UTC, which overrides the property.
    setenv("TZ", "UTC", 1);
    // issue reinit command. KISS argument parsing.
    if ((argc > 1) && argv[1] && !strcmp(argv[1], "--reinit")) {
        return issueReinit();
    }

    static const char dev_kmsg[] = "/dev/kmsg";
    fdDmesg = android_get_control_file(dev_kmsg);
    if (fdDmesg < 0) {
        fdDmesg = TEMP_FAILURE_RETRY(open(dev_kmsg, O_WRONLY | O_CLOEXEC));
    }

    int fdPmesg = -1;
    bool klogd = __android_logger_property_get_bool(
        "logd.kernel", BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_PERSIST |
                           BOOL_DEFAULT_FLAG_ENG | BOOL_DEFAULT_FLAG_SVELTE);
    if (klogd) {
        static const char proc_kmsg[] = "/proc/kmsg";
        fdPmesg = android_get_control_file(proc_kmsg);
        if (fdPmesg < 0) {
            fdPmesg = TEMP_FAILURE_RETRY(
                open(proc_kmsg, O_RDONLY | O_NDELAY | O_CLOEXEC));
        }
        if (fdPmesg < 0) android::prdebug("Failed to open %s\n", proc_kmsg);
    }

    // Reinit Thread
    sem_init(&reinit, 0, 0);
    sem_init(&uidName, 0, 0);
    sem_init(&sem_name, 0, 1);
    pthread_attr_t attr;
    if (!pthread_attr_init(&attr)) {
        struct sched_param param;

        memset(&param, 0, sizeof(param));
        pthread_attr_setschedparam(&attr, &param);
        pthread_attr_setschedpolicy(&attr, SCHED_BATCH);
        if (!pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)) {
            pthread_t thread;
            reinit_running = true;
            if (pthread_create(&thread, &attr, reinit_thread_start, nullptr)) {
                reinit_running = false;
            }
        }
        pthread_attr_destroy(&attr);
    }

    bool auditd =
        __android_logger_property_get_bool("ro.logd.auditd", BOOL_DEFAULT_TRUE);
    if (drop_privs(klogd, auditd) != 0) {
        return -1;
    }

    // Serves the purpose of managing the last logs times read on a
    // socket connection, and as a reader lock on a range of log
    // entries.

    LastLogTimes* times = new LastLogTimes();

    // LogBuffer is the object which is responsible for holding all
    // log entries.

    logBuf = new LogBuffer(times);

    signal(SIGHUP, reinit_signal_handler);

    if (__android_logger_property_get_bool(
            "logd.statistics", BOOL_DEFAULT_TRUE | BOOL_DEFAULT_FLAG_PERSIST |
                                   BOOL_DEFAULT_FLAG_ENG |
                                   BOOL_DEFAULT_FLAG_SVELTE)) {
        logBuf->enableStatistics();
    }

    // LogReader listens on /dev/socket/logdr. When a client
    // connects, log entries in the LogBuffer are written to the client.

    LogReader* reader = new LogReader(logBuf);
    if (reader->startListener()) {
        exit(1);
    }

    // LogListener listens on /dev/socket/logdw for client
    // initiated log messages. New log entries are added to LogBuffer
    // and LogReader is notified to send updates to connected clients.

    LogListener* swl = new LogListener(logBuf, reader);
    // Backlog and /proc/sys/net/unix/max_dgram_qlen set to large value
    if (swl->startListener(600)) {
        exit(1);
//.........这里部分代码省略.........

// Foreground waits for exit of the main persistent threads
// that are started here. The threads are created to manage
// UNIX domain client sockets for writing, reading and
// controlling the user space logger, and for any additional
// logging plugins like auditd and restart control. Additional
// transitory per-client threads are created for each reader.
int main(int argc, char *argv[]) {
    fdDmesg = open("/dev/kmsg", O_WRONLY);

    // issue reinit command. KISS argument parsing.
    if ((argc > 1) && argv[1] && !strcmp(argv[1], "--reinit")) {
        int sock = TEMP_FAILURE_RETRY(
            socket_local_client("logd",
                                ANDROID_SOCKET_NAMESPACE_RESERVED,
                                SOCK_STREAM));
        if (sock < 0) {
            return -errno;
        }
        static const char reinit[] = "reinit";
        ssize_t ret = TEMP_FAILURE_RETRY(write(sock, reinit, sizeof(reinit)));
        if (ret < 0) {
            return -errno;
        }
        struct pollfd p;
        memset(&p, 0, sizeof(p));
        p.fd = sock;
        p.events = POLLIN;
        ret = TEMP_FAILURE_RETRY(poll(&p, 1, 100));
        if (ret < 0) {
            return -errno;
        }
        if ((ret == 0) || !(p.revents & POLLIN)) {
            return -ETIME;
        }
        static const char success[] = "success";
        char buffer[sizeof(success) - 1];
        memset(buffer, 0, sizeof(buffer));
        ret = TEMP_FAILURE_RETRY(read(sock, buffer, sizeof(buffer)));
        if (ret < 0) {
            return -errno;
        }
        return strncmp(buffer, success, sizeof(success) - 1) != 0;
    }

    // Reinit Thread
    sem_init(&reinit, 0, 0);
    sem_init(&uidName, 0, 0);
    pthread_attr_t attr;
    if (!pthread_attr_init(&attr)) {
        struct sched_param param;

        memset(&param, 0, sizeof(param));
        pthread_attr_setschedparam(&attr, &param);
        pthread_attr_setschedpolicy(&attr, SCHED_BATCH);
        if (!pthread_attr_setdetachstate(&attr,
                                         PTHREAD_CREATE_DETACHED)) {
            pthread_t thread;
            reinit_running = true;
            if (pthread_create(&thread, &attr, reinit_thread_start, NULL)) {
                reinit_running = false;
            }
        }
        pthread_attr_destroy(&attr);
    }

    if (drop_privs() != 0) {
        return -1;
    }

    // Serves the purpose of managing the last logs times read on a
    // socket connection, and as a reader lock on a range of log
    // entries.

    LastLogTimes *times = new LastLogTimes();

    // LogBuffer is the object which is responsible for holding all
    // log entries.

    logBuf = new LogBuffer(times);

    signal(SIGHUP, reinit_signal_handler);

    {
        char property[PROPERTY_VALUE_MAX];
        property_get("ro.build.type", property, "");
        if (property_get_bool("logd.statistics",
                   !!strcmp(property, "user")
                && !property_get_bool("ro.config.low_ram", false))) {
            logBuf->enableStatistics();
        }
    }

    // LogReader listens on /dev/socket/logdr. When a client
    // connects, log entries in the LogBuffer are written to the client.

    LogReader *reader = new LogReader(logBuf);
    if (reader->startListener()) {
        exit(1);
    }

//.........这里部分代码省略.........

//.........这里部分代码省略.........
        if (!pthread_attr_setdetachstate(&attr,
                                         PTHREAD_CREATE_DETACHED)) {
            pthread_t thread;
            reinit_running = true;
            if (pthread_create(&thread, &attr, reinit_thread_start, NULL)) {
                reinit_running = false;
            }
        }
        pthread_attr_destroy(&attr);
    }

    if (drop_privs() != 0) {
        return -1;
    }

    // Serves the purpose of managing the last logs times read on a
    // socket connection, and as a reader lock on a range of log
    // entries.

    LastLogTimes *times = new LastLogTimes();

    // LogBuffer is the object which is responsible for holding all
    // log entries.

    logBuf = new LogBuffer(times);

    signal(SIGHUP, reinit_signal_handler);

    if (property_get_bool("logd.statistics",
                          BOOL_DEFAULT_TRUE |
                          BOOL_DEFAULT_FLAG_PERSIST |
                          BOOL_DEFAULT_FLAG_ENG |
                          BOOL_DEFAULT_FLAG_SVELTE)) {
        logBuf->enableStatistics();
    }

    // LogReader listens on /dev/socket/logdr. When a client
    // connects, log entries in the LogBuffer are written to the client.

    LogReader *reader = new LogReader(logBuf);
    if (reader->startListener()) {
        exit(1);
    }

    // LogListener listens on /dev/socket/logdw for client
    // initiated log messages. New log entries are added to LogBuffer
    // and LogReader is notified to send updates to connected clients.

    LogListener *swl = new LogListener(logBuf, reader);
    // Backlog and /proc/sys/net/unix/max_dgram_qlen set to large value
    if (swl->startListener(600)) {
        exit(1);
    }

    // Command listener listens on /dev/socket/logd for incoming logd
    // administrative commands.

    CommandListener *cl = new CommandListener(logBuf, reader, swl);
    if (cl->startListener()) {
        exit(1);
    }

    // LogAudit listens on NETLINK_AUDIT socket for selinux
    // initiated log messages. New log entries are added to LogBuffer
    // and LogReader is notified to send updates to connected clients.

    bool auditd = property_get_bool("logd.auditd",
                                    BOOL_DEFAULT_TRUE |
                                    BOOL_DEFAULT_FLAG_PERSIST);
    LogAudit *al = NULL;
    if (auditd) {
        al = new LogAudit(logBuf, reader,
                          property_get_bool("logd.auditd.dmesg",
                                            BOOL_DEFAULT_TRUE |
                                            BOOL_DEFAULT_FLAG_PERSIST)
                          ? fdDmesg
                          : -1);
    }

    LogKlog *kl = NULL;
    if (klogd) {
        kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, al != NULL);
    }

    readDmesg(al, kl);

    // failure is an option ... messages are in dmesg (required by standard)

    if (kl && kl->startListener()) {
        delete kl;
    }

    if (al && al->startListener()) {
        delete al;
    }

    TEMP_FAILURE_RETRY(pause());

    exit(0);
}

// Foreground waits for exit of the three main persistent threads that
// are started here.  The three threads are created to manage UNIX
// domain client sockets for writing, reading and controlling the user
// space logger.  Additional transitory per-client threads are created
// for each reader once they register.
int main() {
    int fdDmesg = -1;
    char dmesg[PROPERTY_VALUE_MAX];
    property_get("logd.auditd.dmesg", dmesg, "1");
    if (atol(dmesg)) {
        fdDmesg = open("/dev/kmsg", O_WRONLY);
    }

    if (drop_privs() != 0) {
        return -1;
    }

    // Serves the purpose of managing the last logs times read on a
    // socket connection, and as a reader lock on a range of log
    // entries.

    LastLogTimes *times = new LastLogTimes();

    // LogBuffer is the object which is responsible for holding all
    // log entries.

    LogBuffer *logBuf = new LogBuffer(times);

    char dgram_qlen_statistics[PROPERTY_VALUE_MAX];
    property_get("logd.dgram_qlen.statistics", dgram_qlen_statistics, "");
    if (atol(dgram_qlen_statistics)) {
        logBuf->enableDgramQlenStatistics();
    }

    // LogReader listens on /dev/socket/logdr. When a client
    // connects, log entries in the LogBuffer are written to the client.

    LogReader *reader = new LogReader(logBuf);
    if (reader->startListener()) {
        exit(1);
    }

    // LogListener listens on /dev/socket/logdw for client
    // initiated log messages. New log entries are added to LogBuffer
    // and LogReader is notified to send updates to connected clients.

    LogListener *swl = new LogListener(logBuf, reader);
    // Backlog and /proc/sys/net/unix/max_dgram_qlen set to large value
    if (swl->startListener(300)) {
        exit(1);
    }

    // Command listener listens on /dev/socket/logd for incoming logd
    // administrative commands.

    CommandListener *cl = new CommandListener(logBuf, reader, swl);
    if (cl->startListener()) {
        exit(1);
    }

    // LogAudit listens on NETLINK_AUDIT socket for selinux
    // initiated log messages. New log entries are added to LogBuffer
    // and LogReader is notified to send updates to connected clients.

    // failure is an option ... messages are in dmesg (required by standard)
    LogAudit *al = new LogAudit(logBuf, reader, fdDmesg);
    if (al->startListener()) {
        delete al;
        close(fdDmesg);
    }

    pause();
    exit(0);
}